


please don't punch my brother

by nessismore



Category: Marvel Cinematic Universe
Genre: Alternate Universe - Family, Darcy is Tony's Sister AU, F/M, Fluff, Secret Relationship
Language: English
Status: Completed
Published: 2013-02-19
Updated: 2013-02-19
Packaged: 2017-11-29 20:06:26
Rating: Teen And Up Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 2,039
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/690928
Author URL: https://archiveofourown.org/users/nessismore/pseuds/nessismore
Summary: <blockquote class="userstuff">
              <p>A pleasant welcome home is interrupted when big brother finds out just who little sister is dating.</p>
            </blockquote>





	please don't punch my brother

**Author's Note:**

  * For [Merideath](https://archiveofourown.org/users/Merideath/gifts).



> Written for merideath's prompt, "Darcy is Tony’s little sister. She and Steve are secretly dating. Tony finds out and isn’t pleased."
> 
> Unbeta'd.

Steve is sore and dead tired. The threat hanging over Los Angeles has finally been neutralized, and they can finally go home. It’s been too dangerous and there’s been too much to for any of them to call home, and as far as everyone knows, Tony and Thor are the only ones with people to call anyway. 

But Steve knows that Darcy must be sick with worry by now, and not just about her idiot brother. He takes out his phone and shoots her a quick text, wishing he could call instead. But Tony is there, and so are the others, and he isn’t sure how Tony would take to finding out that his little sister is dating Captain America. He and Tony aren’t always on the best of terms anyway, and he’d rather not have that relationship strained even further until he and Darcy are ready bring their relationship out into the open.

Across the way, Tony is on the phone being his usual brash self and, in all likelihood, teasing a smile out of whoever he’s talking to. “Give your love to the team?” he’s saying. “Why would you want to give your love to anyone but me?” Steve listens intently, but he can’t make out what’s being said on the other end, or who’s saying it. “I know. Missed you, too, and I’ll see you when I get back.” Tony pauses. “Yes, I can guarantee you that no one is hurt or seriously injured…Okay…Okay, mom…Yes, we’ll call the second we reach New York air space. I probably won’t remember, but JARVIS will…Right. Love you, too.”  

Tony hangs up and catches Steve staring. “That one’s a worrier,” he says, rolling his eyes.

Steve tries not to look too interested. “Pepper or Darcy?”

“The squirt. She says to give the team her love, but I don’t think she could possibly mean to include you.”

“Thanks, Tony,” Steve says dryly. He doesn’t like hearing that Darcy worries, but it’s kind of nice being fussed at. He can’t wait to get home so that she can do it in person. His phone buzzes a second later. It’s Darcy.

_Tony better not be lying, soldier. If you’re not fine, I’ll kick his ass, then I’ll kick yours._

He tries to hide his smile as he texts back.

 _I’m fine. I promise. Nothing that won’t heal by the time I get home._ Home being the apartment that they just moved into together. Tony doesn’t quite yet know that his baby sister has moved out of the place in Stark Tower that he set up for her a few years ago.

It takes a moment before his phone buzzes again.

_I love you, you know. Get home quick._

He types, _love you too_ , and hits send. When he looks up, he finds Tony staring at him. “I know that grin, Cappie.” Steve just barely stops himself from reaching up to check if he’s smiling. He probably is, because just thinking of Darcy makes him grin like an idiot. Tony is studying him, then his eyes light up and he snaps his fingers. “You’ve got yourself a girlfriend.”

Steve freezes. “What?”

“Don’t deny it. I know the signs. You’re in loooooooove.” Tony draws out the last syllable and makes a heart with his fingers. Steve rolls his eyes.

“Dont,” Steve mutters. He doesn’t want to talk about this, because he’s never been great at lying about his personal life. And even if he _wasn’t_ dating Tony’s little sister, he wouldn’t want to talk about his relationships with Tony. Especially not about this relationship.

“Who is she?”

Steve sighs irritably. “She’s none of your business.”

“So you admit there _is_ a girl!” Tony crows triumphantly. Steve sighs. He fires off another text message to Darcy.

 _Your brother is a pain in the ass_.

She responds a moment later. _I know. But I guess we kind of love him?_

 _I kind of love YOU_. It’s shmoopy and ridiculous, but he can’t help sending it. There’s a longer pause before his phone buzzes again.

 _If you were here right now, we’d both be naked_. 

He stifles a groan and puts his hands in his lap to hide the reaction _that_ image conjures up, because the tights hide nothing. If Tony sees that, Steve is never hearing the end of it. And if he realizes who made him that way, Steve’s pretty sure Tony would punch his lights out, because even if Tony always says that he’s not “that kind of big brother,”  Steve doesn’t really believe him. In fact, he’s pretty sure that if Tony found out that anyone so much as _thought_ of his little sister naked, he’d punch them. He hates to think about what Tony would do if he ever finds out that naked Darcy is something Steve sees—and touches—regularly.

He spends the rest of the flight ignoring Tony’s questions. Then, when Clint and Thor hear what’s going on, he’s dodging them, too. He can’t even get up and join Natasha in the cockpit because Darcy keeps sending him increasingly racy texts, and he just can’t _not_ look when his phone buzzes. This time when it does, it’s a picture of her naked. He turns bright red, and not from embarrassment.

“What did your ladylove send you now, Capsicle?” Tony demands.

Clint snickers and says, “The color he’s turning, I’m not sure our Capsicle is cold right now.” 

Tony cranes his neck to get a look at what’s on Steve’s phone, and he hollers, “Is that a naked woman?”

“No!” Steve grits his teeth, holds his phone away from them, and texts Darcy to behave.

Her next message reads, _i’ll show you how well behaved i am when you get home._

He laughs and is distracted enough that when Tony tries to grab his phone, his fingers brush against it. Steve pulls it away and runs for the cockpit, visible hard-on be damned. He can hear Clint and Tony howling behind him and he’s pretty sure they saw Steve’s obvious reaction to Darcy’s texts. He sits with Natasha for the rest of the flight, and even though she teases him a little, he can take that because she knows about him and Darcy. 

They land at the airport because not even Tony can get a landing strip built on the tower in the middle of the city. Tony salutes them all and flies back, eager to see Pepper, while the rest of them board a helicopter. Of course, even with Tony gone, Clint’s still making fun of him. Steve swears if he calls him “Captain Boner” one more time, he’s going to personally find out if Hawkeye can fly. Before his patience snaps, however, they land at the helipad at Stark Tower. As if realizing Clint’s precarious position, Natasha hurries him along, and Thor follows. Steve is the last one out of the chopper and the only one still on the roof when Darcy comes running through the door to jump into his arms. She wraps herself around him, and kisses him for all she’s worth. Soon he has her backed up against the door of the helicopter.

“Missed you,” she sighs against his lips.

“Missed you, too.” He nuzzles the crook of her neck and moves beneath her, creating delicious friction for them both. “Let’s go inside.”

Darcy shakes her head. “Too far. There’s no one else here. Let’s live on the edge, Cap.” And because he’s already on the edge, it doesn’t take much to convince him. She’s unbuttoning her blouse and devouring his mouth when they hear a voice behind them shouting.

“God damnit, what the fucking hell?”  

They turn and see Tony standing there, still in the Iron Man suit. Pepper bursts through the roof door a moment later, looking apologetic. “He saw you on the surveillance cameras. I’m sorry, I couldn’t stop him.”

Tony glares at Pepper. “ _You_ knew about this?”

“Oh, give it a rest, Tony,” Darcy mutters, sliding down Steve’s body. This is a really inappropriate time to react, but he can’t help but groan, which has Tony staring daggers at him. She looks up at Steve. “Please don’t punch my brother,” she whispers. He nods, content to let her handle this. Darcy turns back to Tony. “Look, Steve and I are dating. Deal with it.”

“Looks like you’re doing more than dating,” Tony mutters darkly.

“Yes,” Darcy says, taking Steve’s hand in hers. “Sometimes we have sex. Actually, we have sex pretty often. It’s really great sex.” Steve fights the urge to cover her mouth, because he’s pretty sure this isn’t helping matters. But he smiles, too, because he always enjoys hearing that Darcy likes what he does with her.

“Darcy Lewis—“ Steve snorts. Tony sounds like a scandalized spinster aunt and not at all like Tony Stark: genius billionaire playboy philanthropist. It’s funny to see the tables turned. Darcy smiles, continuing on like she hasn’t heard her big brother speak.

“It’s a great relaxer, too. Maybe you should try it some time. Oh wait, I’m sure you have.”

“You shouldn’t even be having sex,” Tony mutters, and Steve has to hold tight to Darcy’s hand to keep her from punching her brother. “You shouldn’t know anything about sex.”

Darcy pouts at Steve when he grabs hold of both her arms, preventing her from going for her taser. He’s tempted to let her. “You do realize I’m twenty-four and not fourteen, right? I’ve known what sex is for a while. You might still see me as a twelve-year-old, but you don’t have to protect me from the dangers of sex.”

Tony flinches every time she says “sex.” Darcy smiles gleefully, and Steve thinks this is where the family resemblance really shines through. “Sex, sex, sex, sex, sex,” she shouts, laughing when Tony covers his ears.

Clint, Natasha, and Thor poke their heads through the door to the roof. “Who’s having sex?” Clint demands.

“Steve and me,” Darcy announces, then looks at Steve apologetically. She plants a soft kiss on Steve’s jaw. “I’m sorry, babe, I know you wanted to keep it private.”

“Nah, as long as I get to keep you.” This draws a sigh from her (and, surprisingly, Clint), and a snarl from Tony. Steve hugs her tight. He would have liked to keep their relationship between them, but he doesn’t mind it being out in the open so much. Now he doesn’t have to hide it when he wants to kiss her, so he does. It’s just a gentle thing on the top of her head. It’s nice, and it’s enough to make Tony growl a little and take a menacing step forward. Steve thinks he might have to punch him after all when suddenly Tony slumps forward.

They see Natasha standing there, looking bored. “Pressure points,” she explains when Darcy looks concerned. “He’ll be fine."

Pepper sighs. “It’s probably for the best. Thor, if you wouldn’t mind? You can leave him in our room. Darcy, Steve, I’ll call when he wakes. If you’re going to keep…doing what you were doing, you might want to think about doing it in your apartment.” 

She leads the others back inside, and Steve can hear Thor asking, “The Captain and Lady Darcy are lovers?” before the door shuts behind them.

“Tony’s an ass,” Darcy mutters, turning to lean into Steve’s arms. He runs his hands up and down her back in a soothing motion. “I can’t believe he had the nerve to talk about my sex life. Our sex life.”

“Damn. And we just started getting along, too,” Steve says solemnly, drawing a laugh from her.

She sobers, concern furrowing her brow. “Are you okay with us being out in the open now?”

He leans down kisses her nose. “I’ll live. Like I said, as long as I’ve got you, I’m good.”

She presses her lips to his, and he takes over the kiss, dipping his tongue into her mouth and teasing until she slumps pleasantly against him. “Mmm, you are good, My dumb ass big brother should be out for a while. What do you say we go inside and finish what we started?”

Steve smiled. “I say yes.”


End file.
